In previous studies, the sequence of sugars in the repeating unit of the Groups A, A-variant and C streptococcal polysaccharides were determined. In similar studies on the Group B polysaccharide, the composition and nature of the linkages of its component monosaccharides have been analyzed. This carbohydrate contains 1-linked rhamnose, 1,2-linked rhamnose, 1,2,4-linked rhamnose, 1,3-linked galactose, 1,3-linked N-acetylglucosamine and glucitol-phosphate. The linkages of glucitol phosphate are as yet undetermined.